In this phase III trial, HIV-infected women diagnosed with CIN I by cervical biopsy will be randomized to either oral isotretinoin or observation for 6 months. Randomized subjects on both arms will be followed to the study termination to assess persistence/recurrence or progression of CIN I. Subjects who reach an endpoint of CIN II or III that is confirmed by a biopsy by central pathology review may be eligible for protocol ACTG 200 or they may be followed by their personal gynecologist. The primary objective: To determine the efficacy of oral isotretinoin for prevention of progression of mild dysplasia to more severe dysplasia by comparing the time to progression of CIN I to CIN II, III, or invasive cancer in subjects receiving isotretinoin vs. observation. The secondary objectives: To determine the efficacy of oral isotretinoin for the treatment of CIN I by comparing the proportion of subjects who are free of dysplasia at 6 months among those receiving isotretinoin vs observation; and to assess the adverse effects and toxicity or oral isotretinoin in HIV-infected women. Tertiary objectives: To correlate baseline CD4+ and CD8+ cell counts with time to progression to CIN II, III, or invasive cancer. To document potential differences between progression and/or regression of subjects who are being treated for primary vs recurrent dysplasia.